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A uniform heating wire of resistance 36 Ω is connected across a potential difference of 240 V. The wire is then cut into half and a potential difference of 240 V is applied across each half separately. The ratio of power dissipation in first case to the total power dissipation in the second case would be 1:x where x is ______.

Asked in JEE Main 1st Sept 2nd Shift 2021 · Heating and power in resistors

Answer: 4

Step-by-step solution

First case: P₁=(240²)/(36)=1600 W.

Each half is 18 Ω: (240²)/(18)=3200 W each, total 6400 W.

Ratio 1600:6400=1:4, so x=4.

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